Incontinence – involuntary loss of urine from urinary tract
(Nocturnal) enuresis – discrete episodes of urinary incontinence during sleep, in children over 5, in the absence of congenital or acquired neurological disorders
Monosymptomatic (nocturnal) enuresis – night time incontinence with no other symptoms – i.e. no other daytime urinary symptoms, no urgency or other bladder dysfunction
- Primary MSE – never been dry at night
- Secondary MSE – was dry at night, then becomes wet – may be social trigger or organic (UTI, OSA, DM)
Non monosymptomatic enuresis – bedwetting at night, with any daytime symptoms including urgency, voiding symptoms or daytime incontinence
Approach
The main goal of work-up of paediatric incontinence is to identify and exclude structural (anatomical) and neurological causes. The majority of presentations are functional, but structural and neurological causes must be excluded.
Day time and night time incontinence require different approaches.
Attaining night time continence is a normal developmental process, with significant age variation.
Normal paediatric continence
During infancy – voiding is a reflex act mediated and coordinated at brainstem level – detrusor contractions with relaxation of the sphincter.
This reflex voiding can be disturbed in cases of obstruction (PUV) or reflux.
During first year infants void approx. 20 x day, then around 11 x day next two years, the down to 5 x day by age 7. This is due to increase in bladder capacity.
Successful toilet training depends on the development of voluntary inhibition of the voiding reflex.
Day time bladder co-ordination and control usually occurs by 4 years of age.
Night time continence takes a bit longer – not expected until 5 – 7 years old.
- 5 – 10 % of 7 year olds have NE
- More common in boys
- 15 % will get better each year.
- Increased risk in children with behavioural issues or those with family history of NE.
Work-up
History:
- Onset of incontinence
- ?Primary or secondary – i.e. were they ever dry
- Age of initial continence
- If have never been dry or continuous incontinence – think structural
- Day time symptoms
- Urgency, polyuria, dysuria, UTI symptoms, straining, poor flow
- Timing of symptoms – with laughter, post-void (vaginal reflux)
- Bedwetting – trends/characterise
- How many nights/week
- Time of night
- Arousal levels
- Volume
- Fluid intake (caffeine, polydipsia)
- Holding manoeuvres (Vincent’s curtsy)
- UTIs
- Bowel habits
- Sleeping arrangements
- Medical history and concomitant conditions (OSA, DM, developmental/behavioural)
- Family history of bedwetting, renal failure
- Social history and family dynamics
Examination:
- General exam, syndromic features
- Growth restriction
- Developmental status
- Hypertension / BP
- Abdomen – palpable bladder, palpable constipation
- Genitalia/perineum
- Epispadias, labial adhesions, circumcised, meatal stenosis
- Lower back / spine
- Spina bifida or tethered cord, gluteal atrophy
- Neurological – lower limbs, gait
Investigations:
- Urine dipstick +/- culture
- Bladder diary
- Flow rate and post-void residual
- X-ray for constipation
- Ultrasound
- Indicated if failing conservative management or red flags (continuous incontinence, UTIs)
- Might show elevated residual, thick walled bladder, bladder capacity, duplex
- Rarely (selectively) – MRI spine, cystoscopy, urodynamics
Potential organic causes
- UTI
- Spinal neurological disease – spina bifida occulta, tethered cord
- Labial adhesions
- Ectopic ureters in girls
- Outflow obstruction – PUV, urethral stricture or meatal stenosis post circumcision or hypospadias surgery, anterior urethral valve, syringocele
Monosymptomatic nocturnal enuresis
Pathogenesis – a maturational delay in the ultimate development of bladder control – may be a disruption in any of kidney (nocturnal polyuria), bladder (reduced capacity/overactivity) or brain (disorder affecting arousal or circadian rhythm).
Management strategies:
Usually self limiting with no specific treatment required, particularly before age 6 (5 – 10 % of 7 years olds have nocturnal enuresis).
Decision on when to start treatment is a joint decision with parents & child based on level of bother.
- Conservative:
- Night time fluid restriction
- Elimination of caffeine
- Positive behavioural reinforcement
- Treat constipation
- Alarms
- Successful in 60 – 75 % of cases and usually long-lasting
- Medications
Desmopressin
- Synthetic analogue of ADH – reduces urine production by increasing urine reabsorption
- 2 mg one hour before bed, titrating up to 0.4 mg – intranasal option available
- Main risk is water intoxication / hyponatraemia – administer at night and no oral intake
- Works better when combined to alarms
- High relapse rate when stopped (may use on school camps, etc)
Imipramine
- Decrease time in REM sleep, stimulate ADH and have weak anticholinergic properties
- Not often used due to neural (poor sleep/anxiety) and cardiac conduction risks
Oxybutynin
- More useful in those with daytime frequency or as combination with desmopressin
Other functional voiding syndromes
Overactive bladder
- Majority of daytime urgency and incontinence secondary to overactivity, typically and end of filling
- Often associated with holding manoeuvres
- Must differentiate from dysfunctional voiding (which may develop secondarily from attempting to contract sphincter against overactivity)
- Rx:
- School note
- Education and information
- Bladder retraining
- Treat the bowels / avoid constipation
- Anticholinergics
- Active bladder retraining with physiotherapist
- ?Botox and SNS
Vaginal reflux
- Incontinence soon after voiding in girls – with no other symptoms
- Rx with education, positional modification, exclude adhesions
Giggle incontinence
- Typically in girls aged 9 – 12
- Largely self-limiting, but can respond to oxybutynin or Ritalin
Pollakiuria
- Excessive urinary frequency, but limited to daytime only
- Usually self-limiting, education and reassurance
Dysfunctional voiding / non-neurogenic DSD / non-neurogenic-neurogenic bladder / Hinman syndrome
- External sphincter contraction or closure against a contracting detrusor
- Intermittent flow, stop-start stream
- Incomplete voiding is common
- Associated with reflux, bowel dysfunction
- May progress to bladder wall changes (trabeculation/sacculation), upper tract dilation, and renal compromise
- Also associated with UTIs
- Rx may require physio, timed voiding, biofeedback, CISC, anticholinergics, alpha blockers, all bespoke